Instructions for Inserting Dual-Flow Tubes



Preparation of materials:
  • Sump Tube or NeoSump Gastric Aspirator - (Sump tube & 30ml trap)
  • Stethoscope
  • Hypoallergenic tape
  • Adhesive tape
  • Syringe
Preparation of patient:
  • Measure the length of the tube that should be inserted. It is the sum of the distance from the tip of the nose to the ear lobe and from the ear lobe to the xiphoid process. This position may be marked on the tube with the adhesive tape.
Introduction:
  • The tube is advanced into a nare in a direction parallel to the bridge of the nose. The introduction is stopped when the adhesive tape marker reaches the nare.
Test to show correct positioning:
  • Two tests are used to make sure that the tube is in the correct position:
  • Gastric contents may be aspirated through the tube with a syringe.
  • Bubbles may be heard with a stethoscope applied to the epigastric pit, if air is injected into the tube.
  • Other signs show that the tube has taken the wrong route into the trachea:
  • Bubbles form when the proximal end is placed in a glass of water.
  • Prolonged coughing.
  • If a wheezing sound is heard when the tube is held close to the ear, the tube should be withdrawn immediately.
Attachment:
  • The tube may be fixed to the nose using the hypoallergenic tape.
  • On an older patient, the tube may be pinned to the patient's shirt.
  • Attachment should enable the tube to adopt a natural position and there should not be excessive pressure on the nostrils.
Suction:
  • The green port is connected to the suction source and the blue port is the ventilation port and is left open. If using the NeoSump Gastric Aspirator, the aspirator will already be connected to the green port. The suction tubing will be connected to the side nozzle of the aspirator.
  • Suction pressure with a single lumen tube should never be greater than 25mm Hg: the capillary fragility threshold. With a double lumen sump tube, suction pressure may reach 40 - 60mm Hg without any risk of damaging the gastric mucosa.
  • Two rules must be respected with double lumen tubes to prevent any reflux of aspirate via the small ventilation lumen:
    • The blue connector of the ventilation lumen should always be above the level of the patient's stomach. (a)
    • Unless the final receptacle (not the 30ml trap) for the aspirate has a non-return valve, it should be below the level of the patient's stomach. (b)
Aspirate measurement:
  • The 30ml trap, attached directly to the sump tube is used to measure the amount of aspirate suctioned from the patient's stomach. To ensure accuracy of measurement it should be kept in as near an upright position as possible. This will prevent the aspirate from being suctioned directly from the trap, into the wall-line receptacle.
Additional information:
  • Reference to the insertion and care of gastric tubes may be found in the "Atlas of Procedures in Neonatology - 2nd edition," by Dr M.A. Fletcher, Dr M.G. MacDonald & Dr G.B. Avery, and in "Neonatal Intensive Care," by Merenstein & Gardner.